Return Value

If a SqlGeography instance is user-created, the STPointN method returns the point specified by expression by ordering the points in the order in which they were originally input.

If a SqlGeography instance is constructed by the system, STPointN returns the point specified by expression by ordering all the points in the same order they would be output: first by geography instance, then by ring within the instance (if appropriate), and then by point within the ring. This order is deterministic.

If this method is called with a value less than 1, it throws an ArgumentOutOfRangeException.

If this method is called with a value greater than the number of points in the instance, it returns null.